WARNING: Graphic image. The bird was butchered and cooked before its remains were dumped close to the river

One of the Queen's swans has been found killed and barbecued on the riverbank near to Windsor Castle.

The cooked swan's carcass was dumped near Baths Water, and was discovered by Wendy Hermon, 46, a volunteer for charity Swan Lifeline, which cares for sick and injured birds.

She described the scene as 'sickening', and admitted she would have been distraught if her young son was with her when she made the grisly discovery after being called out by a council warden last Sunday.

"I felt sick when I saw it," she said.

"How can someone do that and leave it where they did? I would have been devastated if I had been walking along there with my little boy and he had seen that.

"It just sickens me that there are people out there that do things like that.

"We could see that whoever did this had taken the breast out.

"It was done neatly, presumably to get at the meat. We have no idea how it was killed, it could have been shot or beaten."

Swan Lifeline/PA

Gruesome: One of the Queen's swans which was apparently "barbecued"

It is considered an offence to kill a wild mute swan as it is believed they are the property of the Crown, though centuries ago, their meat was considered a delicacy.

The birds are now protected under under the Wildlife and Countryside Act 1981 and killing or injuring a swan used to be classed as treason under a law dating back to the 12th century.

Thames Valley Police confirmed it is investigating the gruesome find.

A spokesman said: "Thames Valley Police is investigating a theft following a report at 12.38pm on August 18 by a Royal Borough of Windsor and Maidenhead Council warden who had found a swan.